President Abdrabuh Mansur Hadi has dramatically restructured Yemen's military to curb the influence of those linked to toppled strongman Abdullah Ali Saleh with strong US and Gulf backing.

In a series of decisions announced late on Wednesday, Hadi scrapped the elite Republican Guard commanded by Saleh's oldest son Ahmed and removed Saleh's nephew, Yehya, from his powerful post as deputy chief of central security.

Hadi took the reins of power in Yemen less than a year ago, after veteran strongman Saleh stepped down under a power transition agreement mediated by the Gulf Cooperation Council, following a year-long uprising against his rule.

"Restructuring the army is a must," GCC chief Abdulatif al-Zayani told Hadi by phone, congratulating him on the steps "tied to implementing the Gulf initiative... and UN Security Council resolutions," Saba state news agency said.

Zayani stressed "the support of GCC states for those decisions," it said.

The United States praised the moves as "advancing the goal of a unified, professional military that serves the Yemeni people," presidential counterterrorism adviser John Brennan said in a telephone call with Hadi.

Brennan conveyed President Barack Obama's "support for President Hadi's steadfast resolve to continue on the path of political transition... (and) commended Yemen's ongoing preparations for an inclusive National Dialogue," a White House statement said.

And in Sanaa, thousands of people demonstrated in Sanaa to express their support for Hadi's move.

"No immunity -- Saleh must face justice," they chanted.

With the restructuring of the military and elimination of the powerful Republican Guard, there are now just three main branches: the army, navy and air force.

Three new structures were also created and placed under the presidency's direct control: a presidential guard, special operations forces and a unit in charge of ballistic weapons.

"These decisions are a step towards regaining control of the armed forces, and uniting them," said Yemeni military analyst Muhsen Khossrof.

"They bring all military units under the authority of the ministry of defence, which means abolishing power centres and multi-allegiances in the army."

Hadi's bold measures could not have been taken without GCC and international backing to challenge Saleh's powerful loyalists, analysts say.

"It is a major decision and he (Hadi) understands that he could not do that alone," said security and defence expert Mustafa Alani.

Hadi received UN backing in a Security Council resolution in June threatening sanctions against groups seen to be undermining Yemen's political transition, Alani pointed out.

He also received GCC support through a stern warning that the immunity granted to Saleh and his aides, as part of the exit deal, could be withdrawn. "There was a serious threat that this immunity could be removed," said Alani.

But the success of those measures is not guaranteed, he warned.

"This task is not going to be easy... Military power in Yemen is not the monopoly of the state. Every tribe is a military unit," he said, stressing the ability of various heavily armed groups to challenge central authority.

But Hadi's decisions are unlikely to be challenged, according to Khossrof: "It is not an option to reject those decisions, because that would mean a civil war, and that is not acceptable, regionally and internationally."

The director of the presidential office, Nasr Mustafa, said Yemen's new military structure also excludes the First Armoured Division, led by General Ali Mohsen al-Ahmar who defected and backed the uprising against Saleh.

"The Republican Guard and the First Armoured Division are no more," he said, according to Almasdar Online news website.

The fate of the leaders of the two forces was not immediately known. "Other steps, more important, will have to deal with the fate of general Ali Mohsen al-Ahmar and Ahmed Ali Abdullah Saleh," said Khossrof.

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